Incidence, Clinical Characteristics, and Management of Psoriasis Induced by Anti-TNF Therapy in Patients with Inflammatory Bowel Disease: A Nationwide Cohort Study.

Background: Psoriasis induced by anti-tumor necrosis factor-α (TNF) therapy has been described as a paradoxical side effect.

Aim: To determine the incidence, clinical characteristics, and management of psoriasis induced by anti-TNF therapy in a large nationwide cohort of inflammatory bowel disease patients.

Methods: Patients with inflammatory bowel disease were identified from the Spanish prospectively maintained Estudio Nacional en Enfermedad Inflamatoria Intestinal sobre Determinantes genéticos y Ambientales registry of Grupo Español de Trabajo en Enfermedad de Croh y Colitis Ulcerosa. Patients who developed psoriasis by anti-TNF drugs were the cases, whereas patients treated with anti-TNFs without psoriasis were controls. Cox regression analysis was performed to identify predictive factors.

Results: Anti-TNF-induced psoriasis was reported in 125 of 7415 patients treated with anti-TNFs (1.7%; 95% CI, 1.4-2). The incidence rate of psoriasis is 0.5% (95% CI, 0.4-0.6) per patient-year. In the multivariate analysis, the female sex (HR 1.9; 95% CI, 1.3-2.9) and being a smoker/former smoker (HR 2.1; 95% CI, 1.4-3.3) were associated with an increased risk of psoriasis. The age at start of anti-TNF therapy, type of inflammatory bowel disease, Montreal Classification, and first anti-TNF drug used were not associated with the risk of psoriasis. Topical steroids were the most frequent treatment (70%), achieving clinical response in 78% of patients. Patients switching to another anti-TNF agent resulted in 60% presenting recurrence of psoriasis. In 45 patients (37%), the anti-TNF therapy had to be definitely withdrawn.

Conclusions: The incidence rate of psoriasis induced by anti-TNF therapy is higher in women and in smokers/former smokers. In most patients, skin lesions were controlled with topical steroids. More than half of patients switching to another anti-TNF agent had recurrence of psoriasis. In most patients, the anti-TNF therapy could be maintained.